Another paper using 2,4-D

Another paper using 2,4-D. I am planning on using 2,4-D injection after pollination with some rose crosses just to see if normally sterile crosses will be made fertile. I am planning on letting the hips mature on the plant.

In a second set of experiments I will try to inject a chromosome doubling agent and then 2,4-D, again letting the hip develop on the plant.

Title: An assessment of doubled haploid production in soft red winter wheat by wheat x corn wide crosses.

Authors: Sharma, H.; Yang, Y.; Ohm, H.

Authors affiliation: Dept. Agronomy, Purdue University, West Lafayette, IN, 47901, USA.

Published in: Cereal Research Communications, volumn 30, pages 269-275, (2002).

Abstract: “Feasibility of wheat x corn hybridization to produce doubled haploids (DHs) for soft red winter wheat (SRWW) breeding was assessed. Seven intervarietal wheat hybrids were pollinated with the same corn genotype (Seneca 60) in a greenhouse, followed by 2,4-D application, 6-24 hours post-pollination, embryo rescue at the end of third week after pollination and chromosome doubling by colchicine in the media at 1-2 leaf stage of the plantlets. The plantlets were transferred to soil, maintained in a growth chamber for two weeks and then grown in the greenhouse. There was no seed set without 2,4-D treatment and 81-90% (mean 87%), including proliferated ovaries, with 100 ppm 2,4-D treatment. Wheat hybrids differed significantly for percent seed set with corn pollination and for percent seeds with embryos but not for differentiation of cultured embryos. Haploid seed development was better in coin envelops than in glassine bags. 16% seeds had embryos, 37% embryos had normal organogenesis, 50% seedlings survived to maturity and 25% of them set seed. Wheat hybrid 5156 was the best with 86% seed set, 35% seeds with embryos, 54% embryos producing plantlets of which 57% survived to maturity and 50% of the survivors set seed. Overall, if 100 DHs are needed for selection of desirable segregants, enough intervarietal wheat hybrid seed would be required to have 289 plants of an intervarietal cross for pollination with corn.”


Very interesting tricks indeed. I’ve tried some of them and found them successful with other crops. Hopefully many of us will be willing to give them a try.

For wide potato crosses I’ve used kinetin (a cytokinin) after pollination to extend embryo development before abortion so embryo rescue occured and it helped and I got a wide hybrid. 2, 4D (the herbicide with mainly auxin-like activity, but a bit of cytokinin-like activity too) also has been very successful with potatoes. It seems like these hormones mimic what the embryo may be generating and prevents fruits from falling while the developing embryos are sensitive, especially in the case of slower growing, somewhat confused embryos from wide crosses.

With lilies warm temperatures are often used to help overcome poor pollen tube growth and self-incompatibility, but also some incongruity (hybrid breakdown) as well. The LA lilies (Easter Lily / Asiatic) hybrids are really difficult to generate as well as the LO (Easter lily / oriental). I generated some LO lilies using warm temperatures and embryo rescue and trust both helped aid in getting them. Also if I take the whole ovary and put it into culture first before excising an individual embryo I get more embryo development before abortion too. For some reason tissue culture sometimes seems to allow the embryo to grow more than if it was on the plant.

I met a woman at this past year’s American Society for Hort Sci meetings (friend of my advisor who learned I love roses) doing callus generation with a couple very popular recent landscape roses (she works for a private company and if I say which you’d probably know which roses they are and I probably shouldn’t say). It’s been challenging for her to regenerate some cultivars through callus, but she’s getting some success and is doing it for the reasons Henry mentioned. It’s nice to know that someone is actually putting some of this technology that’s been generated and reported in the literature into use! It seems so much of it is done for the benefits associated with publication for the authors and their students, but private companies with the germplasm and more resources in some respects seldom adopt such approaches.

I haven’t used these techniques with roses, unfortunately. Hopefully someday I’ll have more freedom with fascilities and time to give some a try. I really love making wide crosses and enjoy the challenge.

Have you tried some of these things Henry? You do some tissue culture, have you tried some of the techniques from Rusli and others that have optimized callus regeneration off of rose leaves in culture? It would be fun to learn how much variability you found if you have.

Thanks Henry for putting good food for thought that can be applied to roses on the forum.



Hi Dave,

I have often used the kinetin spray (commercial tomato blossom set spray - the kinetin based one not the calcium based one) after pollination.

Regarding your question concerning my tissue culture experiments. I have not done anything along this line since I stopped using the sunroom. I never was able to regenerate a whole plant. I had some callus cultures that did produce what looked like the start of top growth. I think that I did post some pictures of those results. However, those were lost in the “attempt to form roots step”. In addition to the problems of what concentrations of what chemicals to use, I had the complication of having to work in an unregulated temperature environment.

The paper which appears, to me, to be the breakthrough paper in this area is the paper reporting the use of methyl laurate:


Title: Methyl laurate and 6-benzyladenine promote the germination of somatic embryos of a hybrid rose

Authors: V. Sarasan, A. Roberts, G. Rout

Authors affiliation: A1 Department of Life Sciences, University of East London, Romford Road, London E15 4LZ, UK

A2 Regional Plant Resource Centre, Bhubaneswar 751015, Orissa, India

Published in: Plant Cell Reports, volumn 20, pages 183 - 186, (2001).

Abstract: " Globular stage somatic embryos were induced in callus cultures of Rosa Heritage 2 Alister Stella Gray on medium containing 13.5